How to steal cards when shuffling cards?

Zheng Taishun, the king of China, recommended the "one-finger flop"

1. Fold the whole deck, put it on the table, and spread it into a uniform belt.

2. Lift the card with your left hand and push it to the right with your index finger.

Due to the thrust, the whole deck turned right one by one.

4. Finally, the whole deck should be turned over.